Effect of pretreatment of wool fabric with keratin on its dyeability with acid and reactive dyes

Keratin has been extracted from wool using ammonium thioglycolate under nitrogen atmosphere and then used for treating wool fabric in the presence of epichlorohydrin as a cross-linking agent. The treated fabrics are then dyed with acid and reactive dyes at various temperatures. Complete exhaustion of these dyes on the treated fibres takes place at room temperature within 20 min. Higher dyeing temperatures result in complete exhaustion of the dyebath within a short time. The dyeing kinetics of the treated fibres are also evaluated. The half dyeing time of the treated samples decreases to <12 s against the 300 s for the untreated ones. The wash and rub fastness of the dyed fabrics have also been assessed. It is found that urea-bisulphite solubility values assure that epichlrohydrin is able to form permanent crosslinks between keratin and wool. Scanning electron micrographs of the treated fabrics disclose formation of very thin keratin layer onto wool surface.